Pan am planner of the soybean aphid Aphis glycines Matsumura (Homoptera, Aphididae) in South Dakota: Impact on soybean Glycine max (L.) Merrill (Fabales, Fabaceae) development and yield

Soybean aphid (Aphis glycines Matsumura) is an invasive soybean pest first discovered in the United States in 2000. The soybean aphid's arrival prompted a demand for research conducted in the United States to improve the understanding of this insect. In August 2001, the soybean aphid was discovered in South Dakota. The objectives of these studies were to measure soybean aphid reproductive potential in South Dakota and determine the effect of soybean aphid injury on soybean growth, development, and yield. Aphid infestations at two soybean development stages [V5 (five trifoliate leaves on main stem) and R2 (full bloom)] and six initial aphid population treatments [0, 10, 50, and 100 aphids/plant (treatments of 1 and 3 aphids/plant were added in 2004)] were monitored during the 2003 and 2004 growing seasons. Comparisons across soybean development stage at infestation and initial aphid population treatments were made on measures of aphid population dynamics (lag and accelerated population growth, maximum rate of population change, peak population, and total days to reach peak population) which were determined using logistic and normal curves. (Abstract shortened by UMI.)...